Lloyd Dean

The Nervous and Endocrine System

AimsBy the end of the lesson you should be able to:

Explain the role of the nervous system

Describe the two parts of the nervous system

State how regular activity can enhance neuromuscular connections and improve motor fitness

List the endocrine glands and hormones involved in exercise preparation and performance

The Role of The Nervous System

Question:

What happens when someone shines a bright light in your eye?

What do you do if you place your hand on something hot, for example an hob on an oven?

This is the role of the nervous system; your brain registers the event after it has happened. When a doctor taps your knee they are testing the involuntary response of the brain!

Actions throughout the body need to be coordinated in an effective and productive way

The nervous system communicates with the body to help this

The nervous system and endocrine systems are the communication super powers!

The Nervous SystemNervous system can be broken down into

Central Nervous System (CNS)Peripheral Nervous System (PNS)

Central Nervous System (CNS)The CNS is the main “switchboard” of the

communication

Brain and spinal cord

Controls the movements of the body by working with the PNS

Interprets stimuli

The Nervous SystemPeripheral Nervous System (PNS)

Consists of all the other neurones outside of the CNS

Communicates and works with, the CNS

Receives the stimuli via senses (Touching hot iron)

Further subdivided into:Sensory Neurones – Transmit impulses from a receptor

to CNSMotor Neurones – Transmit impulses from CNS to

effectors (Muscle or Gland). Further subdivided into:Somatic Nervous System – Involves voluntary movement of

skeletal musclesAutonomic Nervous System – Carries nerve impulses from

CNS to organs.

Autonomic Nervous SystemThis means “self adjusting” and is

involuntary

Is further broken down into:Sympathetic Nervous System – Arouses

the body “Fight or Flight” (Increase HR, vasodilatation)

Parasympathetic Nervous System – Relaxes the body (Decrease HR, vasoconstriction)

What Does Pinky Keep On Saying?!

Enhancing Neuromuscular Connections

The neuromuscular junction (NMJ) is the communication point between the brain and the muscles

Anaerobic training, usually 7 weeks required, can increase the communication and improve motor fitness - HOW?!

Increasing the overall area of NMJ

More dispersed synapse

Increase of acetylcholine receptors

Improving Motor FitnessIncreasing the overall area of NMJ

When the overall area of the NMJ increase more muscle fibres can become recruited, thus increasing strength over a period of time

Training in first 4 weeks

More dispersed synapseA synapses if where two neurones meetThey control the messages sent from the nervous systemThey allow one neurone to stimulate several other

neuronesAn increase can result in more activation of the muscle

Increase of acetylcholine receptorsUsed for skeletal muscle contractionMore of this hormone results in more recruitment of

muscle fibres

Endocrine Glands and Hormones

Understanding endocrine glands and hormones is vital when planning training

Different types of training methods can impact hormonal release and adaptations

Hormones are chemical messengers that are released into the body by endocrine glands

These are released via neural stimulation

Hormones will put body in a anabolic (insulin, testosterone, hgh) or a catabolic state (cortisol, progesterone)

Etherton, (2006)

Endocrine System

Pancreas Adrenal Glands Large, pale coloured gland found

behind stomach

Produces insulin and glucagon

Controls blood glucose levels

Failure to regulate insulin is know as “diabetes mellitus” Mellitus is Latin for honey

Blood glucose mechanisms cannot work properly Type 1 – Unable to produce insulin Type 2 – Cannot produce sufficient

insulin

Sits at the top of the kidneys

Produce adrenaline which is used for fight or flight response

Adrenaline increases the sensitivity of the nervous system

How Can Athletes Manipulate The Endocrine System With Resistance Training (Baechle & Earle, 2008)

General Concepts The more muscle fibres recruited for an exercise, the greater the extent of

potential remodelling process in the whole muscle

To Increase Growth Hormone Levels Use workouts with higher lactate concentrations High intensity (10RM with 3 sets of each exercise and short rest periods) Supplement diet with carbohydrate and protein before and after

workloads

To Increase Testosterone Concentrations Large muscle group exercises (Deadlift, Power Clean, Squats) Heavy Resistance (85 – 95% of 1RM) Short rest intervals (30 – 60 seconds)

To Optimise Responses To Adrenal Hormones Use high volume, large muscle groups and short rest periods but vary the

training protocol and the rest period length and volume to allow the adrenal gland to engage in recovery processes and to prevent a catabolic effect. This will ensure that the stress of training will not result in overtraining or overuse injuries.

AimsYou should now be able to:

Explain the role of the nervous system

Describe the two parts of the nervous system

State how regular activity can enhance neuromuscular connections and improve motor fitness

List the endocrine glands and hormones involved in exercise preparation and performance